What is the distribution of single and multiple herbicide resistance in waterhemp populations across the state of Illinois?

Abstract

The current trend in controlling waterhemp (Amaranthus tuberculatus) populations using herbicides has led to concern about herbicide resistance. The distribution of herbicide resistance in waterhemp populations was investigated. Waterhemp leaf tissue samples were obtained from farmers and weed management practitioners and the DNA was extracted and used for herbicide-resistance assays. Gel/PCR experiments were conducted in order to determine protoporphyrinogen oxidase (PPO) inhibiting herbicide resistance and qPCR experiments were conducted to determine glyphosate resistance. Results showed that the majority of field samples received were resistant to both PPO inhibitors and to glyphosate. Farmers should become aware of the distribution of herbicide resistance in waterhemp populations and change their control tactics to better manage this weed.